Electrical totalizer

ABSTRACT

An electrical totalizer for forming an output signal with occurrences separated by a minimum time interval and representative of the total number of random occurrences in first and second circuits. First and second input circuits receive occurrences from, respectively, such first and second circuits. First and second bistable state circuits respond to separate strobes for changing states for each occurrence at, respectively, the first and second input circuits. A combining circuit is coupled to the first and second bistable state circuits for forming an output representation for each different occurrence at the input circuits. A separator forms, in an output signal, an output occurrence responsive to an applied strobe for each of the output representations. A strobing circuit is operative during repetitive cycles for applying, during each cycle, a strobe to each of the first and second bistable state circuits and to the separator in a predetermined sequence.

BACKGROUND OF THE INVENTION

This invention relates to electrical totalizers and more particularly tototalizers which combine pulses representing power being consumed fromtwo or more different sources and provide output pulses representativeof the total power consumed.

Pulse devices are used in watthour and varhour meters by power companiesand industry to provide pulses, the number of which is proportional tothe power being consumed. The pulses are used for billing purposes aswell as for load management programs. The power companies record signalsrepresenting the power consumed for subsequent billing to the customer.Billing is made according to the peak energy used during some finitetime interval, i.e., 15 minutes, as well as by the time of day that thepeak energy usage occurred. Industrial users employ the pulses as inputto computers for load management programs.

Where two or more circuits are involved, each circuit carries a separateseries of pulses representative of the power being consumed for thecorresponding circuit. Totalizers are known which totalize the pulsesfrom separate circuits into a single channel of totalized pulses forpurposes of recording. In this regard, the single channel of totalizedpulses is commonly recorded on a real time basis on magnetic tape in theform of non return to zero (NRZ) recording. Each transition in flux onthe magnetic tape represents a unit of power consumed. The recordedpulses are later utilized to determine the peak power consumption duringany desired time interval during the day. It is a characteristic of thistype of recording equipment that there be some predetermined minimumtime interval between two successive flux changes or pulses recordedalong the tape. The problem of totalizing is complicated by the factthat the pulses in one circuit may occur simultaneously, overlap, oroccur at most any time separation in relation to the pulses in the othercircuit. Also, there may be bursts of power usage where two pulses inone circuit may occur very close together.

Totalizers are known for totalizing multiple circuits of power pulsesinto a single channel of pulses for recording on tape. One general typeof totalizer of this type now in use is referred to as the MD totalizermanufactured by The General Electric Company and described in GeneralElectric brochure GEH-1050F published May, 1969. The MD type totalizerutilizes synchronous motors driving a differential drive gear assembly.Another type of device manufactured by The General Electric Company isreferred to as the type SST-3 Solid state Totalizer and is described inGeneral Electric brochure GEH-2784A, published April, 1973.

These prior art types of totalizers suffer from a number ofdisadvantages.

SUMMARY OF THE INVENTION

Briefly, an embodiment of the present invention involves an electricaltotalizer for forming output occurrences, such as changes in signals,which are separated by a minimum time interval. The occurrences arerepresentative of first and second randomly applied occurrences such asthe power pulses. The totalizer includes first and second input circuitsfor receiving, respectively, the first and second occurrences. First andsecond bistable state circuits are provided for responding to separatestrobes for changing states for each occurrence at, respectively, thefirst and second input circuits. A combining circuit is coupled to thefirst and second bistable state circuits for forming an outputrepresentation for each different occurrence at both input circuits. Aseparator forms one of the output occurrences, responsive to an appliedstrobe, for each of the output representations. The strobes arerepetitively and sequentially applied, a strobe being applied to each ofthe first and second bistable state circuits and to the separatorsequentially during each repetition.

An embodiment of the present invention is also an electrical totalizerfor forming an output signal with random occurrences at a maximum rateof occurrence and representative of the total number of randomoccurrences separately applied at first and second input circuits.Included are means for sequentially and alternately scanning the firstand second input circuits at a first rate and for producing a series ofoutput representations. An output representation is formed for eachdifferent occurrence applied at either of the first and second inputcircuits. Means provides in an output signal a series of outputoccurrences occurring at a maximum of a second rate. The first rate istwice that of the second rate. One output occurrence is provided foreach of the output representations. Means temporarily stores arepresentation of one of the output representations until an outputoccurrence has been formed for the output representation preceding suchone of the output representations. The means for providing outputsignals is characterized for providing an output occurrence in theseries corresponding to the temporarily stored representation, therebyenabling output occurrences to be reliably formed corresponding to allapplied random occurrences. The applied random occurrences have acombined average rate of occurrence of up to the second rate whichapplied occurrences may be applied at either of the first and secondinput circuits with an average rate of up to the second rate.

A number of advantages over the above mentioned prior art totalizers maybe achieved in such an embodiment of the present invention. These are,by way of example, as follows:

Output occurrences in the order of 900 to 1500 occurrences during a 15minute period can easily be achieved with the present invention, whereasthis is not possible with the MD type totalizer.

The output rate at which pulses are formed by a totalizer is generallylimited to some maximum rate by, for example, the recording rate of therecording device. The rate at which input occurrences are provided mustbe selected so that the totalized occurrences on all input circuits donot exceed that maximum output rate. The present invention will allow asingle input circuit (and any input circuit) to accept the full maximumoutput rate, whereas the MD type device cannot. This is important whenenergy consumption drops at one input circuit and increases on another.

The present invention will operate properly even though one of the inputcircuits is inactive (i.e., no occurrences are formed thereat). Theoperation of the MD type device is adversely affected under theseconditions.

The present invention will accept a two occurrence burst rate which istwice as fast as the maximum output rate for the totalizer. Neither theMD nor the SST type totalizer will accurately totalize under theseconditions.

The present invention may be easily cascaded in the field for more thantwo input circuit use without the need for appreciable additionalcabinet space, merely by the addition of a circuit board. The MD5requires the addition of a bulky motor driven differential system andthe SST type totalizer is not easily modified in the field to increasethe number of input circuits.

The present invention may be cascaded without care being given to thedistribution of load among the various input circuits. By way ofcontrast, the SST type device requires the input circuits receivingoccurrences at a higher rate to be connected to lower numbered inputs.

Significantly the present invention is much simpler and is thereforeexpected to have a much lower failure rate then the SST type device.Because of its simplicity, the present invention requires less spacethan either the MD or SST type of device.

The present invention may be made much simpler and less costly theneither of the aforementioned prior art devices, the same circuit beingusable for both two circuit and more than two circuit jobs. Itssimplicity also allows for easier technician training.

The present invention is significant in that it is substantiallysimplified but yet has increased performance characteristics as comparedwith either the MD device or the SST device.

The separator circuit allows the scan rate or strobe of both bistablestate circuits, taken together, to be twice as fast as the scan rate orstrobe for the separator circuit thereby allowing any one of theindividual input circuits to receive up to the full input design ratefor both input circuits of the totalizer. Additionally the separatorcircuit allows a burst of two successive occurrences at different inputcircuits which occur at a higher rate than the output rate to beretained and output. This is accomplished with an arrangement whereinthe second of the two occurrences in the burst stored and retained arethen output at the output rate determined by the strobe.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a system employing an electrical totalizerfor recording pulses on magnetic tape representing pulses from twoseparate circuits and embodying the present invention;

FIG. 2 is a schematic diagram of an electrical totalizer and depictingthe contacts of the watt-hour meters and embodying the presentinvention;

FIG. 3 is a block diagram of an electrical totalizer system forcombining pulses from three different circuits and embodying the presentinvention; and

FIGS. 4 and 5 are timing diagrams for illustrating the operation of theelectrical totalizers of FIGS. 1, 2 and 3.

DETAILED DESCRIPTION

Refer now to the block diagram of FIG. 1. A totalizer circuit 10according to the present invention has its two inputs connected to a twowire circuit coming from watt-hour meters 12 and 14. The output of thetotalizer is connected to the input of a magnetic tape recorder 16.Generally speaking, each of the watt-hour meters 12 and 14 forms aseries of output pulses as indicated. On a real time basis the pulsesoccur in time so as to represent the actual rate of power consumptionand each pulse represents some preselected unit of power consumption.The pulses are applied to the inputs 18 and 20 of the totalizer 10 whichin turn combines the pulses, from the separate circuits, to form aseries of output pulses at output 15. The total number of output pulsesfrom the totalizer 10 is either equal to or, to be explained, by the useof a divider is proportional to the total number of input pulsesreceived from each of the two watt-hour meters 12 and 14. Thus, 5 inputpulses are depicted at input 18 and 3 input pulses are depicted at input20 whereas a total of 8 output pulses are indicated at output 15. Thetape recorder 16 saturates the magnetic tape in one direction for onepulse at output 15 and in the opposite direction for the next sequentialpulse at output 15, i.e, NRZ recording. This occurs in real time so thatthe pulses along the magnetic tape can be read back to determine thetotal power consumed during any particular time period such as the abovementioned 15 minute time interval.

Refer now to the schematic diagram of the electrical totalizer 10depicted in FIG. 2. For purposes of illustration the circuitry forforming the pulses in each of the watt-hour meters 12 and 14 is depictedat the left hand side of FIG. 1 in dot dash line. The electricaltotalizer 10 includes all of the circuitry of FIG. 2 except for thatdepicted in the dot dash lines. Each of the watt-hour meters includes aset of mercury wetted relay contacts which alternately apply ground totwo conductors of an output circuit. For example, watt-hour meter 12 hasoutput conductors 12a and 12b and watt-hour meter 14 has outputconductors 14a and 14b. Each time a relay contact connects ground to adifferent one of the conductors 12a and 12b, a pulse is formedrepresenting another unit of power consumption. Similar comments applyto the conductors 14a and 14b of watt-hour meter 14. Whenever a unit ofpower is consumed and a relay contact switches ground to a differentconductor, a pulse or occurrence in the input signal is said to occur.

Briefly, electrical totalizer 10 of FIG. 2 forms an output signal atconductor 34 with changes in signal, separated by a minimum timeinterval. Each change in signal on conductor 34 is also referred to asan occurrence. These occurrences are re-formed and represented asoccurrences in the form of contact closures at the output 15 as will bedescribed in more detail hereinafter. The occurrences in the outputsignal on conductor 34 are separated by a minimum time interval andrepresent the total number of random occurrences provided by thewatt-hour circuits 12 and 14 and the rate at which the total of theinput occurrences appear in time. The electrical totalizer 10 has firstand second input circuits 18 and 20 for receiving the occurrences fromthe watt-hour meters 12 and 14, respectively. The first and secondbistable state circuits 22 and 24 respond to separate strobes forchanging states for each occurrence at, respectively, the input circuits18 and 20. Thus, bistable state circuit 22 changes state, responsive toa strobe applied on conductor 26, for each occurrence at the input 18.Similar comments apply as to the bistable state circuit 24 with respectto input circuit 20 when a strobe is applied on conductor 28.

Combining means in the form of an exclusive OR gate 30 is coupled to thebistable state circuits 22 and 24 for forming a different one of twooutput signals, or output representations, for each different occurrenceat the input circuits 18 and 20. Separator means in the form of circuit32 forms an output signal at conductor 34. The separator circuit 32forms an output occurrence in the output signal at conductor 34responsive to a strobe applied at conductor 36 for each of the differentoutput representations from the exclusive OR gate 30.

Means in the form of a clock 38 is operative during repetitive cyclesfor applying, during each cycle, a strobe to each of the bistable statecircuits 22 and 24 and to the separator circuit 32 (via conductors 26,28 and 36). The strobes are applied on the conductors 26, 28 and 36 oneafter the other in a predetermined sequence as will be explained in moredetail hereinafter.

Consider the electrical totalizer circuit 10 in more detail. Thebistable state circuit 22 is coupled to input conductors 18a and 18b,forming the input circuit 18 through an RS type flip flop 40. Similarly,the bistable state circuit 24 is connected to conductors 20a and 20b,forming the input circuit 20, through an RS flip flop 42. The RS flipflop is a signal conditioning circuit that eliminates contact bounce andcontact transition problems inherently present in the contacts in thewatt-hour meters. The RS flip flop 40 has inputs 40a and 40b and anoutput 40c. The RS flip flop is formed of two cross-coupled and latchingAND gates and is characterized in that it will trigger to one of twostates depending on the input which is connected to ground, i.e.,grounded. For example, when ground is connected to input 40a, RS flipflop 40 goes to one state, whereas when input 40b is grounded, it goesto the other state. When RS flip flop 40 is in one state called the "1"state, the output 40c receives what is referred to as a "1" signal,whereas when RS flip flop 40 is in its other state, called the "0"state, the output 40c receives what is referred to as the "0" signal.Such RS flip flops as well known in the art.

The inputs to the RS flip flops 40 and 42 are made more immune tospurious signals by the provision of diodes 52, 54, 56 and 58. It shouldnow be evident that the RS flip flops will alternately trigger from onestate to the other each time the relay contacts in the correspondingwatt-hour meter 12 changes the ground connection from one of theconductors to the other at the corresponding input circuit.

The bistable state circuits 22 and 24 are D-type flip flops. The D-typeflip flops are well known in the digital art and are characterized inthat a signal referred to herein as the "1" signal at the "0" input willcause the flip flop to (1) form a "1" signal at the "Q" output and (2)cause the flip flop to change to what is referred to herein as a "1"state immediately upon the occurrence of a strobe signal (to be defined)at the "C" input. Similarly, the D-type flip flop is characterized inthat a signal referred to herein as the "0" signal at the "D" input willcause the flip flop to (1) form a "0" signal at the "Q" output and (2)cause the flip flop to change to what is referred to herein as a "0"state immediately upon the occurrence of a strobe signal at the "C"input. "1" and "0" signals are complementary, i.e., one a high voltageand the other a relatively lower voltage in relation to the first. Thestrobe is a signal which makes a rapid transition from a low level ofvoltage to a relatively higher value. These voltage values are only usedby way of example.

To be explained in more detail, the flip flops 22 and 24 alternatelyreceive strobes at the "C" inputs on conductors 26 and 28 and as aresult allow for a time separation when simultaneous occurrences occurat the two inputs 18 and 20.

The "Q" outputs of bistable state circuits 22 and 24 are connected tothe input of the exclusive OR gate 30. Significantly, the OR gate 30sums up the occurrences applied at the two inputs 18 and 20 and forms anoutput signal representing the total of the occurrences. The exclusiveOR gate 30 is characterized in that it forms an output signal atconductor 60 representing a "1" whenever the bistable state circuits 22and 24 are in different states. Thus a "1" output is formed by OR gate30 when bistable state circuits 22 and 24 are in "0" and "1" or in "1"and "0" states, respectively. If both of bistable state circuits 22 and24 are in a "0" or "1" state, exclusive OR gate 30 forms a "0" output.

Refer now to the burst separator circuit 32. The burst separator circuit32 includes exclusive OR gate 62 (which is identical to exclusive ORgate 30) and bistable state circuits 64 and 66. Bistable state circuits64 and 66 are both D-type flip flops having identical characteristics tothat described hereinabove with respect to circuits 22 and 24.

Briefly, exclusive OR gate 62 applies a strobe signal to the "C" inputof bistable state circuit 64, causing it to store a signal, i.e., assumea state, corresponding to the output from exclusive OR gate 30. Bistablestate circuit 66 has its "D" input connected to the "Q" output ofbistable state circuit 64 and has its "C" input connected to conductor36 from the output of the clock circuit 38. The "Q" output of flip flop66 is connected to conductor 34 and to one of the inputs to exclusive ORgate 62.

The clock circuit 38 includes a constant frequency oscillator 68 whichapplies its clock pulse signals to a decade counter 70. The decadecounter 70 has ten sequential states referred to as 0,1,2,3,4, 5 through9. At states 0, 3 and 5, respectively, a clock or strobe pulse isapplied, respectively, to the conductors 28, 36 and 26. The leading edgeof the pulse is a positive transition which forms the strobe for thecorresponding bistable state circuits.

From the foregoing description it should be evident that the rate atwhich the strobe circuit 38 strobes both of the bistable state circuits22 and 24 is twice the rate at which the bistable state circuit 66 isstrobed. Stating it differently, a strobe is applied to each of thebistable state circuits 22 and 24 once before a strobe is applied to thebistable state circuit 66.

Briefly, FIG. 2 discloses an electrical totalizer for forming an outputsignal with random occurrences at a maximum rate of occurrence andrepresentative of the total of random occurrences separately applied atthe first and second input circuits 18 and 20. Included is a circuit 120which sequentially and alternately scans the first and second inputcircuits at a first rate, determined by the clock 70, and produces aseries of output representations at 60. An output representation isformed at 60 for each different occurrence applied at either of theinput circuits 18 and 20. The separator circuit 32 forms a means forproviding in an output signal a series of output occurrences at amaximum of a second rate. The output signal is formed at conductor 34. Afirst rate (i.e., pulses applied at the 0 and 5 output of counter 70) istwice that of the second rate (i.e., the rate at which pulses are formedat the 3 output of counter 70). One output occurrence is formed atconductor 34 for each of the output representations formed at conductor60. Bistable state circuit 64 forms means for temporarily storing arepresentation of one of the output representations (formed at conductor60) until an output occurrence has been formed at conductor 34 for theoutput representation which precedes such one of the outputrepresentations. The separator circuit 32 is characterized for providingan output occurrence in the series corresponding to the temporarilystored representation. As a result, output occurrences are reliablyformed corresponding to all applied random occurrences where the appliedrandom occurrences have a combined average rate of occurrence of up tothe second rate. Additionally, the applied occurrences may be applied ateither of the input circuits 18 and 20 with an average rate of up to thesecond rate.

Consider an example of the operation of the totalizer circuit of FIG. 1with reference to the timing diagram of FIG. 4. FIG. 4 depicts thestates of the counter 70, the strobe applied to the "C" input of flipflops 22, 24 and 66, and the signals formed at the outputs 40c and 42cof the RS flip flops 40 and 42, the "Q" outputs of the flip flops 22 and24, 64 and 66, and the outputs of the exclusive OR gates 30 and 62. Theten states 0-9 of the counter 70 are numbered across the top of FIG. 4adjacent the corresponding waveform. FIG. 4 assumes that the relaycontact in watt-hour meter 12 alternates between the conductors 12a and12b and that the relay countact in watt-hour meter 14 does not change.As a result, a series of four changes in signal or occurrences areformed at the output 40c of the RS flip flop 40 and FIG. 4 identifiesthe four occurrences at "40c of 40" by the numerals 1 through 4 with acircle surrounding the number (referred to hereinafter as "in circle").

Occurrence 1 in circle results in a "1" state of RS flip flop 40. Whenthe counter 70 reaches the state 5, which is identified in FIG. 4 as100, the strobe applied at the "C" input of bistable state circuit 22causes it to change from state "0" to state "1". With bistable statecircuit 22 in state "1" it is assumed that bistable state circuit 24 isin state "0". Thus, exclusive OR gate 30 forms a "1" output orrepresentation. The "1" output of exclusive OR gate 30 represents the 1"in circle" occurrence provided by the watt-hour meter 12.

It is also assumed that the bistable state circuit 66 is in a "0" state.Thus, exclusive OR gate 62 receives a "1" input from exclusive OR gate30 and a "0" input from bistable state circuit 66, causing the exclusiveOR gate 62 to go from a "0" to a "1" at its output. The positivetransition at the output of exclusive OR gate 62 forms a strobe for the"C" input of bistable state circuit 64, causing it to change from a "0"to a "1" state. Bistable state circuit 64 now stores a valuecorresponding to the occurrence 1 "in circle".

At counter state "0", designated 102 in FIG. 4, a strobe is applied tothe bistable state circuit 24. However, since it is assumed that nooccurrences are being applied by the watt-hour meter 14, bistable statecircuit 24 remains in a "0" state.

At counter state 3, designated 104 in FIG. 4, a strobe is applied at the"C" input of bistable state circuit 66. Since bistable state circuit 64is in a "1" state, the bistable state circuit 66 is triggered to a "1"state. As designated by the 1 "in circle" in FIG. 4, pulse 1 fromwatt-hour meter 12 has now resulted in an occurrence on conductor 34 atthe "Q" output of bistable state circuit 66.

The "1" output formed at the "Q" output of bistable state circuit 66 incombination with the "1" output of exclusive OR gate 30 causes theoutput of exclusive OR gate 62 to go from "1" to "0", as depicted at 105in FIG. 4, conditioning exclusive OR gate 62 so that the next change inthe output of exclusive OR gate 30 will cause it to apply a strobe tothe "C" input of bistable state circuit 64.

The position of the relay contacts in watt-hour meter 12 changes andcauses the signal at output 40c of the RS flip flop 40 to change to a"0", creating occurrence 2 "in circle". Counter state 5, designated 106in FIG. 4, causes a strobe at the "C" input of bistable state circuit 22and the bistable state circuit 22 is reset to a "0" state. Sincebistable state circuit 24 is already in a "0" state, the newly formed"0" state of bistable state circuit 22 causes the exclusive OR gate 30to in turn form a "0" output. The "0" output of exclusive OR gate 30 incombination with the "1" state of bistable state circuit 66 causes theexclusive OR gate 62 to change its output from a "0" to a "1". Thepositive transition at the output of exclusive OR gate 62 forms a strobeat the input of bistable state circuit 64 causing it to assume a "0"state corresponding to the "0" output of exclusive OR gate 30. Thus,bistable state circuit 64 now stores a value corresponding to theoccurrence 2 "in circle".

Subsequently, counter state 3, designated 108 in FIG. 4, is reached anda strobe is applied at the "C" input of bistable state circuit 66. Thiscauses the bistable state circuit 66 to assume a "0" state correspondingto the state of bistable state circuit 64 and as a result a "0" outputis formed on conductor 34 at the "Q" output of bistable state circuit66, representing the occurrence 2 in circle.

The "0" output formed at the "Q" output of bistable state circuit 66 incombination with the "0" output of exclusive OR gate 30 causes theoutput of exclusive OR gate 62 to go from a "1" to a "0" as depicted at108 in FIG. 4, again conditioning the exclusive OR gate 62 so that thenext change in the output of exclusive OR gate 30 will cause it to applya strobe to the "C" input of bistable state circuit 64. Similar analysiswill apply for subsequent occurrences or pulses 3 "in circle" and 4 "incircle".

Refer now to FIG. 5 and consider the situation where there aresimultaneous occurrences from the two watt-hour meters 12 and 14. Underthese conditions it is assumed that both of RS flip flops 40 and 42 gofrom a "0" to a "1" state and hence "1" signals are formed at both ofthe outputs 40c and 42c. The occurrences are identified as 1 and 2 incircle. At the following counter state 5, designated 110 in FIG. 4, the"C" input of bistable state circuit 22 receives a strobe, causingbistable state circuit 22 to change from a "0" to a "1" state. Thebistable state circuit 24 is in a "0" and accordingly the exclusive ORgate 30, sensing different states in the two bistable state circuits 22and 24, forms a "1" output representing the occurrence 1 in circle. Itis assumed that bistable state circuit 66 is now in a "0" state andaccordingly the exclusive OR gate 62, sensing different valued outputsfrom bistable state circuit 66 and exclusive OR gate 30, changes itsoutput from a "0" to a "1" , forming a strobe at the "C" input ofbistable state circuit 64. The strobe at the "C" input of bistable statecircuit 64 causes it to change to a "1" state corresponding to theoutput of exclusive OR gate 30. Thus, bistable state circuit 64 nowstores a value corresponding to the occurrence 1 in circle.

Subsequently, clock state 0, designated 112 in FIG. 5, causes a strobeat the "C" input of bistable state circuit 24, causing it to change to a"1" state corresponding to the state of bistable state circuit 24.Bistable state circuit 24 now stores a value corresponding to occurrence2 in circle. Bistable state circuits 22 and 24 are now in the samestate, i.e., state "1", causing the exclusive OR gate 30 to form a "0"output corresponding to the occurrence 2 in circle. Since bistable statecircuit 66 is still in a "0" state, the two inputs to the exclusive ORgate 62 are alike, causing the exclusive OR gate 62 to change its outputfrom a "1" to a "0" as depicted at 114 in FIG. 5.

Subsequently the clock state 3, designated 116 in FIG. 5, causes astrobe at the "C" input of bistable state circuit 66. The strobe causesbistable state circuit 66 to be triggered into a "1" state correspondingto the "1" state of bistable state circuit 64. As a result theoccurrence 1 "in circle" 40c has now caused an output occurrence onconductor 34 at the "Q" output of bistable state circuit 66 as indicatedby 1 "in circle".

In addition the bistable state circuit 66 is now storing a "1" and theexclusive OR gate 30 is now forming a "0" output, causing the exclusiveOR gate 62 to apply a strobe to bistable state circuit 64, causing it tochange to a "0" state corresponding to the "0" output of exclusive ORgate 30. Bistable state circuit 64 now stores a value corresponding tooccurrence 2 "in circle".

Subsequently, clock state 3, designated 118 causes a strobe at the "C"input of bistable state circuit 66, causing it to assume a "0" statecorresponding to the "0" state of bistable state circuit 64. As a resulta "0" value is formed on conductor 34 at the "Q" output of bistablestate circuit 66 thereby representing the occurrence 2 "in circle".

In summary then what has been disclosed are two bistable state circuits22 and 24 each for assuming a different state in response to a strobefor each occurrence in an input signal. A clock 70 is provided foralternately strobing the bistable state circuits 22 and 24 at differingtimes. Exclusive OR gate 30 alternately forms output indicationsrepresenting binary "1" and "0" values. A different one of the binaryvalues is formed for each change in state of either one of the bistablestate circuits 22 and 24. Bistable state circuit 64 forms a storagecircuit which is operative, upon an applied strobe, for storing anindication of a binary value "1" for a binary value "1" output from theexclusive OR gate 30 and is further operative for storing an indicationof a binary value "0" for a binary value "0" output from the exclusiveOR gate 30. The bistable state circuit 66 forms a means for reading outthe stored indications in the bistable state circuit 64, and the clock70 enables the readout upon the occurrence of the strobe of both thebistable state circuits 22 and 24. The exclusive OR gate 62 forms meansfor applying a strobe to the bistable state circuit 64 to enable a storeto take place therein upon the coincidence of opposite binary values inthe output from exclusive OR gate 30 as compared with the indication inbistable state circuit 64 which is last read out by the bistable statecircuit 66.

It should now be seen that the bistable state circuit 66 will only readout values from bistable state circuit 64, i.e., form occurrences at theoutput "Q" on conductor 34, whenever clock 70 reaches state 3. Thereforethe occurrences at the conductor 34 cannot occur any closer togetherthan the time for clock 70 to cycle through its complete ten states ofoperation. As a result the burst separator circuit 32 ensures that nooccurrences are formed at the output conductor 34 any closer togetherthan the time for clock 70 to cycle through its ten states of operation.

If it is not required that the pulses formed at output 34 be spaced bysome minimum time interval, then the sub combination indicated at 120 inFIG. 2 can be employed. To this end bistable state circuits 22 and 24,exclusive OR gate 30, and clock 70 can be employed for forming a simpletotalizer circuit for asynchronous occurrences in input signalsoccurring at the two input circuits 18 and 20. The bistable statecircuits 22 and 24 each form a 2 state circuit which assumes a differentstate in response to a strobe for each occurrence in the correspondinginput signal. The clock 70 alternately strobes the two bistable statecircuits 22 and 24 at differing times and at a fixed rate. Exclusive ORgate 30 forms an output indication for each occurrence of apredetermined relation in states between the bistable state circuits 22and 24. For example, whenever the bistable state circuits 22 and 24 arein different states, the exclusive OR gate 30 forms a "1" output,whereas when the bistable state circuits are in the same state, theexclusive OR gate 30 forms a "0" output.

As discussed with reference to FIG. 1, the eletrical totalizer 10 hasits output 15 connected to a magnetic tape recorder 16 which in turn isarranged for recording in NRZ format. Referring to FIG. 2, the output 15has three output conductors 80, 82 and 84. A connection betweenconductors 80 and 82 causes the tape recorder 16 to magneticallysaturate the tape in one direction whereas a connection between theconductors 82 and 84 causes a magnetic saturation in the oppositedirection. The totalizer circuit includes a relay 69 and a relay driver71. The relay driver 71 receives signals from the conductor 34 causingthe relay driver 71 to switch the relay 69 between two states ofoperation. Specifically the relay 69 has a coil 72 and contacts 74, 76and 78. The relay driver 71 energizes the coil 72 in one of twodirections causing the relay to switch the contact 78 either intoelectrical contact with contact 74 or contact 76 thereby shortingtogether conductors 80 and 82 or conductors 82 and 84.

The relay driver 71 has an input conductor 67 connected to the conductor34. Conductor 67 is connected to one input of each of exclusive OR gates90 and 92. Exclusive OR gates 90 and 92 are identical to exclusive ORgate 30 described hereinabove. The other input of exclusive OR gate 90is connected to a ground +V1 source of potential the value of which isequal to the so-called "1" output signal. The exclusive OR gate 92 hasits other input connected to ground potential which is the so-called "0"output signal. As a result the outputs of exclusive OR gates 90 and 92always represent opposite binary values. The binary values representedby the output of exclusive OR gates 90 and 92 switch between values "1"and "0" as the signal on conductor 67 changes between values "1" and"0".

The outputs of exclusive OR gates 90 and 92 are connected through relaydriving transistors 94 and 96, respectively, across opposite sides ofthe coil 72. The exclusive OR gates 90 and 92 and transistors 94 and 96provide alternate polarity of current through the coil 72 therebyalternately driving the relay contacts 74 and 78 and the contacts 78 and76 into contact as the signal on conductor 67 alternates between "0" and"1" values. A capacitor 98 is connected between the emitter oftransistors 94 and 96 and ground in order to prevent high frequencynoise problems.

FIG. 4 depicts the operation of the relay driver 71 and relay 69 withrespect to the example given in FIG. 4. For example, when the "Q" outputof bistable state circuit 66 represents a "1", relay contacts 74 and 78are closed, whereas when the output represents a binary "0", relaycontacts 78-76 are closed.

Similar comments apply to the example of FIG. 5.

It may be desirable to divide the frequency of the occurrences atconductor 34 to a sub multiple, i.e., divide the occurrences so thatonly one half as many or one fourth as many occurrences or contactclosures are formed at the output 15 as compared with the frequency ofoccurrences on conductor 34. To this end a divider 100 is providedhaving an input connected to conductor 34. Divider 100 is a conventionaldivider circuit made up of type D flip flops which divide the inputsignals thereto by 2 or 4. Thus the output identified "÷2" upon receiptof a signal which alternates between "1" and "0" divides the frequencyof that signal by two. The output labeled "÷4" upon receipt of a signalwhich alternates between "1" and "0" divides the frequency of thatsignal by four. In order to divide the frequency of the signal onconductor 34, the conductor 67 is connected to either the ÷2 or the ÷4output from the divider 100.

FIG. 3 depicts an alternate embodiment of the invention in which theelectrical totalizer circuits 10 are cascaded to accommodate threeseparate input circuits. In the three separate circuits, mercury wettedwatt-hour meter contacts 110, 112 and 114 each provide pulsesrepresenting units of power consumed in the same manner described withrespect to the watt-hour meters 12 and 14 of FIG. 2. For ease ofexplanation, one of the electrical totalizer circuits is referred to bythe same reference numerals used in FIG. 1 whereas the other uses thesame numerals with primes.

Referring in more detail to FIG. 3, the electrical totalizer 10 has itsoutput 15 connected to the input 18' of electrical totalizer 10'.Specifically, conductors 84 and 80 at the output 15 are connected,respectively, to the input conductors 18a' and 18b' of electricaltotalizer 10' Conductor 82 at the output 15 is connected to ground,enabling the corresponding relay contacts 74, 78 and 76 (see FIG. 2) toalternately connect the conductors 84 and 80 to ground. The remaininginputs 18 and 20 of totalizer 10 and input 20' of totalizer 10' areconnected to the three separate circuits including the relay contacts110, 112 and 114 in the same manner described with reference to FIG. 2.

With the cascaded electrical totalizer circuits of FIG. 3, theoccurrences formed by relay contacts 110 and 112 are totalized by thetotalizer 10, causing a series of occurrences in the signal at theoutput 15 which are applied to the input of totalizer 10'. Theoccurrences formed in the output signal at 15 are in turn totalized withthe occurrences formed by the relay contacts 114 in the electricaltotalizer 10'. The occurrences in the output signal at 15' represent thesum or total of all of the electrical impulses formed by all of therelay contacts 110, 112 and 114. The output 15' may in turn be connectedto a tape recorder or other monitoring or recording device in order thatthe totalized occurrences can be stored or recorded.

It will be apparent that additional electrical totalizer circuits 10 canbe cascaded. For example, occurrences on four separate circuits can betotalized merely by adding another electrical totalizer 10 connected tothe output of totalizer 10' and by connecting the fourth circuit to theadditional totalizer.

Although an exemplary embodiment of the invention has been disclosed forpurposes of illustration it will be understood that various changes,modifications and substitutions may be incorporated into such embodimentwithout departing from the spirit of the invention as defined by theclaims appearing hereinafter.

What is claimed:
 1. An electrical totalizer for forming an output signalwith occurrences separated by a minimum time interval and representativeof the total number of random occurrences in first and second circuits,comprising:first and second input circuits for receiving occurrencesfrom, respectively, such first and second circuits; first and secondbistable state circuits for responding to separate strobes for changingstates for each occurrence at, respectively, the first and second inputcircuits; combining means coupled to the first and second bistable statecircuits for forming an output representation for each differentoccurrence at both input circuits; separator means for forming in anoutput signal an output occurrence responsive to an applied strobe foreach of the output representations; and means operative duringrepetitive cycles for applying, during each cycle, a strobe to each ofthe first and second bistable state circuits and to the separator meansin a predetermined sequence.
 2. An electric totalizer according to claim1 wherein the combining means comprises means for forming outputrepresentations which differ from one output representation to the next.3. An electric totalizer according to claim 1 wherein the combiningmeans comprises exclusive OR gating means.
 4. An electric totalizeraccording to claim 1 wherein, in order, a burst of first and secondsequential ones of said output representations are formed, the separatormeans comprising:first means for storing, in sequence, first and secondrepresentations of, respectively, the first and second outputrepresentations and for forming, respectively, first and second outputoccurrences in the output signal, each of the first and second outputoccurrences being formed in response to a separate one of the strobesapplied to the separator means; and second means responsive to the firstoutput representation for temporarily storing the first representationand for subsequently transferring a representation thereof to the firstmeans for storing and forming output occurrences, the second means beingoperative upon formation of the first output occurrence for temporarilystoring the second representation and for subsequently transferring arepresentation thereof to the first means for storing and forming outputoccurrences.
 5. An electric totalizer according to claim 1 wherein theseparator means comprises means for forming first and second differentoutput signals, a different one being formed to represent eachsuccessive output representation, and wherein the separator meanscomprisesstorage means for storing first and second different signalscorresponding to, respectively, the first and second output signals;readout means for forming in the output signal an output occurrenceresponsive to the strobe applied to the separator means for each changein the signals stored in the storage means; and means for enabling thestorage means to store upon forming an output occurrence.
 6. An electrictotalizer according to claim 5 wherein the combining means comprisesexclusive OR gating means.
 7. An electric totalizer according to claim 5wherein the means for enabling the storage means comprises exclusive ORgating means having input circuits coupled to the combining means andthe readout means.
 8. An electric totalizer according to claim 7 whereinthe readout means comprises a further storage means.
 9. An electrictotalizer according to claim 8 wherein the storage means and furtherstorage means each comprises a bistable state circuit.
 10. An electrictotalizer according to claim 1 wherein the strobe applying meanscomprises means for applying the first and second strobes with evenlyspaced time intervals therebetween.
 11. An electric totalizer accordingto claim 1 wherein the strobe is applied to the separator means at afixed frequency.
 12. An electric totalizer for forming an output signalwith occurrences separated by a minimum time interval and representativeof the total number of random occurrences in first and second circuits,comprising:a first input circuit for receiving such occurrences from thefirst circuit; a second input circuit for receiving such occurrencesfrom the second circuit; a first bistable state circuit responsive to afirst strobe for changing states for each occurrence at the first input;a second bistable state circuit responsive to a second strobe forchanging states for each occurrence at the second input; means forforming a different output representation upon a predeterminedcombination of states of the first and second bistable state circuits;separator means for forming in an output signal an output occurrenceresponsive to an applied third strobe for each of the outputrepresentations; and means operative during repetitive cycles forapplying, during each cycle, the first, second and third strobes in apredetermined sequence.
 13. An electric totalizer for forming an outputsignal with occurrences separated by a minimum time interval andrepresentative of the total number of random occurrences in first andsecond circuits, comprising:a first input circuit for receivingoccurrences from such first circuit; a second input circuit forreceiving occurrences from such second circuit; a first bistable statecircuit responsive to a first strobe for changing states for eachoccurrence at the first input circuit; a second bistable state circuitresponsive to a second strobe for changing states for each occurrence atthe second input circuit; exclusive OR gating means coupled to the firstand second bistable state circuits for forming output representations; athird bistable state circuit having an output and responsive to a thirdstrobe for changing to a state corresponding to the outputrepresentation of the exclusive OR gating means; gating means responsiveto a fourth strobe and the third bistable state circuit for forming inan output signal an occurrence; further exclusive OR gating means havinginputs coupled to the exclusive OR gating means and to the output signalfrom the gating means for applying the third strobe to the thirdbistable state circuit; and means operative during repetitive cycles forapplying, during each cycle, the first, second and fourth strobes in apredetermined sequence.
 14. A circuit for totalizing simultaneous and/ornon simultaneous occurrences in input signals occurring at separateinput circuits and for providing readout signals separated by a minimumtime interval, comprising:a first two state circuit for assuming adifferent state in response to a strobe for each such occurrence in afirst input signal; a second two state circuit for assuming a differentstate in response to a strobe for each such occurrence in a secondinput; a clock for alternately strobing said first and second two statecircuits at differing times; means for alternately forming outputindications representing binary "1" and "0" values, a different value ofoutput indication being formed for each change in state of either one ofsaid first and second two state circuits; a storage circuit operative,upon an applied strobe, for storing an indication of a binary value "1"for a binary value "1" output indication and for storing an indicationfor a binary value "0" for a binary value "0" output indication; meansfor reading out the stored indications of binary values "1" and "0" andcomprising clocking means to enable the readout upon the occurrence ofthe strobe of both said first and second two state circuits; and meansfor applying a strobe to said storage circuit to enable the storetherein upon the concurrence of opposite binary values in the outputindication as compared with the stored indication that is last read outfrom the storage circuit.
 15. An electrical totalizer for forming anoutput signal with random occurrences at a maximum rate of occurrenceand representative of the total number of random occurrences separatelyapplied at first and second input circuits thereof, comprising:means forsequentially and alternately scanning the first and second inputcircuits and for producing a series of output representations having arate of occurrence of up to a maximum of a predetermined rate, an outputrepresentation being formed for each different occurrence applied ateither of the first and second input circuits, each of the inputcircuits being so scanned at one half said predetermined rate; means forproviding in an output signal a series of output occurrences occurringat a maximum of one half said predetermined rate, one output occurrencebeing provided for each of the output representations; and means fortemporarily storing a representation of one of the outputrepresentations until an output occurrence has been formed for theoutput representation preceding such one of the output representations,the means for providing output signals being characterized for providingan output occurrence in the series corresponding to the temporarilystored representation thereby enabling output occurrences to be reliablyformed corresponding to all applied random occurrences, the latterhaving a combined average rate of occurrence of up to one half saidpredetermined rate which applied occurrences may be applied at either ofthe first and second input circuits with an average rate of up to onehalf said predetermined rate.